Launched in 1999, “VISION 2020: The Right to Sight” is a collaborative global initiative by the World Health Organization (WHO) and the International Agency for the Prevention of Blindness (IAPB) with the twin aims of eliminating avoidable blindness by the year 2020 and preventing the projected doubling of avoidable visual impairment.[1] The goal of this initiative was to integrate a sustainable, comprehensive, high-quality, equitable eye care model into a strengthened national health-care system.[1] The World Health Assembly (WHA) in 2006 adopted resolution WHA 59.25, “Prevention of avoidable blindness and visual impairment,” creating a global mandate for VISION 2020, and followed it up with Resolution WHA 62.1, the “Action Plan for the Prevention of Blindness and Visual Impairment, 2009–2013.”[1] The WHA further endorsed a Global Action Plan (GAP) for Universal Eye Health in 2013, which set a target to reduce the prevalence of avoidable blindness and visual impairment by 25% from the baseline of 2010, with cataract as the priority.[2] The WHO GAP-adopted quantifiable measures for cataract surgical service delivery are cataract surgical rate (CSR – number of cataract surgeries performed per year per one million population) and cataract surgical coverage (proportion of people with bilateral cataract eligible for cataract surgery who have received cataract surgery in one or both eyes at 3/60 and 6/18 visual acuity level).[2] The WHO and IAPB initiatives have helped clear the blurred vision of policymakers and implementers and in galvanizing the process of objectively tracking the data and improving cataract surgical service delivery.

What Is the Load of Cataract Blindness?

Globally, cataract is the single most important cause of blindness, and the second most common cause of moderate and severe vision impairment (MSVI) according to the Global Burden of Disease, Injuries and Risk Factors Study. Cataract contributed to a worldwide 33.4% of all blindness and 18.4% of all MSVI.[3] Translating the same into actual numbers, cataract caused blindness in 10.8 million of overall 32.4 million blind and visual impairment in 35.1 million of 191 million visually impaired individuals.[3] These figures were lower in the high-income countries (<15%) as compared to South and Southeast Asia (>40%).[3]

Is the Trend Changing?

From 1990 to 2010, the number of blind and visually impaired people due to cataract decreased by 11.4% and 20.2%, respectively, and the age-standardized global prevalence of cataract-related blindness and MSVI reduced by 46% and 50%, respectively.[3] During the same period, the total number of cataract surgeries more than tripled in the world and the CSR increased in all regions, especially in Asia, with improvement of surgical techniques and a lower rate of complications.[4],[5]

How Much More Do We Have to Do?

The wishful aim is to operate sufficient cataracts each year so that everyone with an operable cataract (visual loss justifying surgery) can be benefited. There are three factors that influence the volume of cataract surgery – population age dynamics (age >60 years), visual acuity threshold used as an indication for surgery, and the proportion of those who are eligible for surgery to those who actually undergo surgery.[6]

A recent United Nations World Population Ageing report states that the number of people in the world aged >60 years is projected to grow by 56%, from 901 million in 2015 to 1.4 billion in 2030 and 2.1 billion by 2050.[7] A similar trend is expected in India, with rise in the percentage of population aged >60 years set to rise from 8.9% in 2015 to 12.5% in 2030 and 19.4% in 2050.[7],[8] Absolute numbers are more striking – an increase from 116 million in 2015 to 191 million in 2030 and 330 million in 2050.[7],[8] Increase in life expectancy will compound the situation.[8] Coupled with the fact that the rate of rise in aging population outstrips the rate of supply of trained ophthalmologists, aging India will keep our cataract surgeons busy.

George Gilder, author of Wealth and Poverty, emphasized that in economics, increased demand is due to an increase in a new, inventive supply that exceeds people's expectations.[9] This concept, as put in perspective by Erie, is reflected in the current demand–supply situation for cataract surgery at least in urban India.[9] Riding high on technology and trends and adopting refractive cataract surgery using a safe and a reliable painless surgical technique with minimal postoperative care has duly exceeded patient expectations and has fueled the demand for cataract surgery. This phenomenon has also brought down the visual acuity threshold for cataract surgery. Increasing patient demand will keep our cataract surgeons busy.

The third but a challenging aspect is to provide access to cataract surgery for the underserved population and ensuring optimal outcome in this subgroup. Globally, it is recognized that the cataract burden assumes disproportionately daunting proportion with lower socioeconomic conditions. Urban–rural imbalance in the distribution of ophthalmologists and suboptimal training of residents in cataract surgery (shortage of adequately trained workforce) add to the problems. India has been successful in raising its CSR from around 700 in 1981 to 6000 in 2012.[10] This is much closer to the estimated CSR of 8000–8700 needed to eliminate blindness due to cataract in India.[10] However, it is of concern that several states (Jammu and Kashmir, Jharkhand, Bihar, Northeastern states, Odisha, Chhattisgarh, West Bengal, and Karnataka) are lagging in implementing the reasonable targets fixed by the National Program for Control of Blindness (NPCB) despite proactive support by the government and the nongovernmental organizations.[11]

The traditional camp approach has several variables that are difficult to standardize to deliver uniformly safe and effective outcome. Operating cataracts in surgical camps and by visiting surgeons with suboptimal preoperative screening, inappropriate sterilization techniques, unreliable follow-up and tardy identification of complications can do more harm than good. Vision-threatening complications in such a setting may have serious medico-legal implication on the surgical team. The spectacular success of measures to strengthen the rural eye care delivery system by vertically integrated, comprehensive, volume-optimized, protocol-based, standardized, safe, cost-effective, sustainable, high-quality, and equitable hub-and-spokes model of hospital-based cataract surgery by trained and skilled workforce in several parts of the country should encourage replication of similar models in the needy populations. While all these happen, even if each AIOS member were to perform one cataract surgery a day, we will eminently meet the NPCB annual target.

India is right on the top of the cataract heap. While we have brilliantly excelled in quickly adopting to the sunrise technology and the global trends in ensuring patient delight that far exceeds their expectations, we have severely lagged behind in providing basic care to the underprivileged populations. While we have created innovative, cost-effective, and self-sustaining rural eye care delivery models that are put on a pedestal and duly acclaimed by the rest of the world, we are unable to replicate these in several parts of the country where there is an actual need. The disparity is obvious and needs to be bridged by conscious and concerted efforts.